the time is always displayed without AM or PM. That is, if a message is posted at 15:30 in the afternoon, it displays '03:30 CDT'...
displayed as 'military' (24 hour clock) Central time
Well, as I suspected, things were a bit odd at the server. After a fairly long phone conversation with the hosting company, the tech found where there had been several time and time zone issues on a RedHat server on which the site in question lived. A sister server running Debian didn't have these issues. It required 90 minutes of downtime, but they transfered the entire account to the Debian box, and BINGO! Not only does AM/PM now show up, the 12/24 config setting works to show 'military' time if set to '24' and actually shows the correct hours between 13 and 23. Praise the Lord and pass the Zantac!